Lactic acid is produced in your muscles and builds up during intense exercise. It can lead to painful, sore muscles. Lactic acid buildup due to exercise is usually temporary and not cause for a lot of concern, but it can affect your workouts by causing discomfort.

Why does lactic acid build up cause soreness?

A side effect of high lactate levels is an increase in the acidity of the muscle cells, along with disruptions of other metabolites. The same metabolic pathways that permit the breakdown of glucose to energy perform poorly in this acidic environment.

Is lactic acid the culprit that causes soreness?

Lactic acid is a normal byproduct of muscle metabolism, but it can irritate muscles and cause discomfort and soreness. Muscle soreness associated with exercise is known as delayed onset muscle soreness or DOMS.